Create a custom action with EMPTY CommandUIDefinition, so that it overrides existing ribbon button.

Lets stick with the last one!

Add Custom Action to Hide Open with Explorer:
While any ribbon button, group, tab can be hidden by overriding the specific custom action using Visual Studio based solution as in How to Hide SharePoint 2010 Ribbon Button, Group, Menu, Tab, Here I'm using PowerShell to add/remove custom action to hide Open with Explorer view in SharePoint 2013.Add custom action to disable Open with Explorer button in SharePoint 2013: